What is colon cancer?
Colon cancer (also called colorectal cancer or bowel cancer) is the abnormal development of cells in the colon or rectum. Colon cancer occurs in men and women at any age however 90% of new cases occur in people 50 years of age or older.
- Signs & Symptoms
When symptoms appear, they will vary due to size and location of the cancer.
Signs and symptoms of colon cancer include:
- A change in bowel movements lasting longer than four weeks (e.g. diarrhea, constipation)
- Rectal bleeding
- Bloody stools
- Lingering abdominal discomfort such as gas or cramping
- Weakness and fatigue
- Unexplained weight loss
- Diagnosis of Colon Cancer
The Centers for Disease Control recommends men and women between the ages of 50 and 75 be screened regularly for colon cancer. Tests include:
- Fecal Occult Blood Test: The fecal occult blood test (FOBT) is used to detect blood in the stool. Patients receive a test kit for obtaining a small sample of stool at home and return the kit to be tested. Patients are screened yearly.
- Flexible Sigmoidoscopy: A health care professional inserts a short, narrow, flexible, lighted tube into a patient's rectum. This allows the health care professional to check for polyps or cancer. Patients are screened every three to five years.
- Colonoscopy: This procedure is similar to the flexible sigmoidoscopy except with a longer tube. The doctor searches and removes most polyps and some cancers. Colonoscopy may also follow up another screening test if anything unusual is found. Patients are screened every ten years.
- Double-Contrast Barium Enema
- Virtual Colonoscopy
- Stool DNA Test
- Talking With Your Doctor
Radiation oncologists and medical oncologists are the most common physicians who treat cancer. However, physician assistants (PAs), nurse practitioners (NPs), nurses, nutrition specialists, social workers and other health and hospital professionals may be a part of your treatment team.
Some questions you might consider asking a health care professional include:
- Exactly what type of cancer do I have?
- What are my chances of survival?
- How much experience do you have treating this type of cancer?
- What are my treatment choices?
- Causes and Risk Factors of Colon Cancer
Cancer researchers do not know the exact causes of colon cancer but they have discovered some factors that may lead to its development.
- Inherited gene mutations
- Acquired gene mutations
Several factors might increase the risk of getting colon cancer. These include:
- Being overweight or obese
- Physical inactivity
- Heavy alcohol use
Risk factors that you cannot change include:
- Being older
- Personal history of colorectal polyps or cancer
- Personal history of inflammatory bowel disease
- Family history of colon cancer
- Prevention of Colon Cancer
Research continues for how to prevent colon cancer. A few ways that may reduce your chances include:
- Regular screenings
- Reducing red meat intake
- Calcium, vitamin D or folate supplements
- Smoking cessation
- Abstaining from alcohol
- Stages of Colon Cancer
- Stage 0: The cancer has not grown beyond the inner layer of the colon or rectum, or spread to the lymph nodes, organs or other areas.
- Stage I: The cancer has grown through the layers of the colon or rectum but not spread to nearby lymph nodes or distant sites.
- Stage II: The cancer may have grown into or through the outermost layers of the colon or rectum. It may have reached nearby organs and tissues but not spread to the lymph nodes or distant organs.
- Stage III: The cancer may have grown into or through the outermost layer of the colon or rectum and into nearby organs or tissues. The cancer has spread to lymph nodes near the site of the primary tumor. The cancer has not metastasized to distant sites.
- State IV: The cancer has metastasized to distant sites, such as the liver or lungs. The cancer may or may not have grown through the wall of the colon or rectum, and lymph nodes may or may not have been affected.
- Treatment Options For Colon Cancer
Working and speaking with your doctor will help determine which treatment option will be the best for you.
Surgical excision is the most common treatment for colon cancer. Part of the healthy colon or rectum and nearby lymph nodes will also be removed.
A radiation oncologist uses high-energy x-rays to destroy cancer cells. This is commonly used for treating colon cancer because these tumors tend to recur near their origin.
Targeted therapy targets the cancer's specific genes, proteins or the tissue that contributes to cancer growth and survival. This treatment blocks the spread of cancer cells while limiting damage to healthy cells.
Chemotherapy is the use of drugs to stop the cancer cells' ability to grow and divide. Medical oncologists, doctors who specialize in treating cancer with medication, usually administer chemotherapy.
- Prognosis of Colon Cancer
When discussing patients with Stage I, II, III or IV colon cancer, the five-year survival rate for each is:
- Stage I: The five-year survival rate is around 92%
- Stage II: The five-year survival rate is between 63% and 87%
- Stage III: The five-year survival rate is between 53% and 89%
- Stage IV: The five-year survival rate is around 11%